Select the number from among the given options that can replace the question mark (?) in the following series.
13, 17, 26, 51, ?, 221
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. 100
Given series: 13, 17, 26, 51, ?, 221
The series follows this pattern:
13 + 22 = 13 + 4 = 17
17 + 32 = 17 + 9 = 26
26 + 52 = 26 + 25 = 51
51 + 72 = 51 + 49 = 100
100 + 112 = 100 + 121 = 221
So, the missing term in the series is 100.
Hence, 100 is the correct answer.